Experimental assessment of Acanthopagrus schlegelii biomass based on environmental DNA technology

The Environmental DNA (eDNA) technology has attracted significant attention due to its convenience and high sensitivity. However, the variations of eDNA across diverse environments and biological species remain complex. Therefore, a detailed exploration of the release patterns of eDNA for specific species under different environments is crucial for the scientific utilization of eDNA detection techniques. This study conducted an experiment involving the aquaculture of Acanthopagrus schlegelii to explore the release and degradation mechanisms of eDNA. It also analyzed the influence of salinity and biomass on the concentration of eDNA in water. Through model simulations, the variation patterns of A. schlegelii eDNA were revealed. The study achieved three key findings: (1) The research on the release and degradation mechanisms of A. schlegelii eDNA indicated that the Generalized Additive Model (GAM) effectively fits the variation patterns of eDNA concentration. The peak concentration of eDNA released by A. schlegelii was observed at 42 h, and the degradation process exhibited two stages: rapid and slow degradation, with a negative correlation between eDNA concentration and time. (2) By investigating the relationship between the concentration of A. schlegelii eDNA and biomass, it was demonstrated that Linear Models (LM) effectively captured this relationship, indicating a correlation between eDNA concentration and biomass. (3) The detection of A. schlegelii eDNA concentration under different salinity conditions revealed that the GAM model better reflected the relationship between eDNA and salinity, exhibiting a negative correlation. As salinity increased, the concentration of eDNA decreased. This study lays a foundation for future assessments of the A. schlegelii biomass in natural waters using eDNA quantitative detection techniques, and provides relevant references for quantitative eDNA detection techniques in other marine fish species.